Meet Molly..

  Meet Molly... She is a automatic wet swiffer.. She works in conjunction with my commercial roomba that I love..

  I wanted a simple robot that would pick up where the roomba left off.. In other words to do the mopping in my house.. I could have purchased the companion to roomba known as scooba but that would not have been in true "LetsMakeRobots" form..lol

  This is another arduino project.. I am using motors salvaged from another roomba (they are great little motor/wheel/encoder combos) with a Polulu MD03A controller (great product).. The controller is an Arduino mega 1280 (cause I had it laying around).. Other sensors include an IR wall sensor, front bumper sensors and software torque sensing.. The pump and pad on the bottom are from a wetjet swiffer that I destroyed.. The tank was just a small plastic jug I had laying around.. The construction is plexiglass purchased from my local Home Depot and cut with a simple jigsaw.

  Basically at this point it just wanders around randomly changing directions when encountering and object.. At a random time or when stuck it will go into wall following mode for a random amount of time.. It squirts out a small amount of floor cleaner approx every 10 sec when traveling forward only. That's about it at this point..

  The one cool feature that I implemented is a torque sensor which is capable of detecting a struck object that is missed by the bumpers.. In essence I am monitoring if the torque delivered to the motors is higher than a threshold consider this a bump condition..

Navigate around cleaning the floor


This is a companion discussion topic for the original entry at https://community.robotshop.com/robots/show/meet-molly

Neat! I hope it cleans your
Neat! I hope it cleans your floors well.

Do you have something to keep it on the linoleum?

Torque sensor?

I am a little curious about your torque sensor, I am in the middle of putting a chasis together but am waiting on my sensors to arrive, that sounds like a great “in the meantime” plan. Any chance you can tell us how you implemented it?

Hey my dad should get advice from you.
You should know my dad tried building a robo mop. Nice job you actually completed it. He gave up a year ago.

**Sure… **

   For sure… it is really quite simple… I am using the encoders to calculate speed… Then I command the robot to move forward at a specific speed … As a test I check the average PWM that the speed calculation is outputting to drive the robot at the required speed… Then I put a catch in my bumper routine that says if torque is above threshold consider it a bump…

   Since it is only driving around on smooth floors then it is quite reliable as a non mechanical bump sensor…

hmm…

  I actually have only hardwood and ceramic tile on my main floor where it cleans… Not even sure what I would do for a sensor for that…?? hmmmm…